Biomimetically Prepared Antibacterial, Free Radical Scavenging Poly(ethylene glycol) Supported Silver Nanoparticles as <i>Aedes albopictus</i> Larvicide

Abstract

Mosquito borne diseases like malaria and dengue are common menace across the tropics. Furthermore, many bacterial diseases are highly predominant in these areas. Conventional approaches that account for combating these issues suffer from environmental and technical problems. In the endeavor to ‘go green,’ we report the tapping of reductive potential of aqueous extract of Colocasia esculenta leaves to prepare poly(ethylene glycol) stabilized silver nanoparticles under ambient conditions. The effects of pH and temperature in the formation of nanoparticles were studied. The nanoparticles were characterized by UV-visible spectroscopy, FTIR and XRD. The silver-nanoparticles were distributed within a narrow size spectrum of (12–14 nm) as revealed by transmission electron microscopic imaging. Antimicrobial potency of the prepared particles was tested against both gram positive and gram-negative bacteria responsible for a wide spectrum of diseases. DPPH scavenging test established the anti-oxidant potency of the prepared silver nanoparticles. The larvicidal activity of the nanoparticles was assessed against the common dengue vector Aedes albopictus. The LC50 and LC90 (95% fiducial limits) were found to be 0.69 (0.66–0.72) and 0.98 (0.92–1.06) mg/L respectively. SEM-EDX analysis vouched for the penetration of the silver nanoparticles leading to the rupturing of the larval cuticle. The prepared multi-potent nanoparticles can have prospective applications in myriad of domains.